21257392029 has 8 divisors (see below), whose sum is σ = 28369172832. Its totient is φ = 14158602960.

The previous prime is 21257392027. The next prime is 21257392049. The reversal of 21257392029 is 92029375212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21257392029 - 2¹ = 21257392027 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21257392027) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3244114 + ... + 3250659.

It is an arithmetic number, because the mean of its divisors is an integer number (3546146604).

Almost surely, 2^21257392029 is an apocalyptic number.

It is an amenable number.

21257392029 is a deficient number, since it is larger than the sum of its proper divisors (7111780803).

21257392029 is a wasteful number, since it uses less digits than its factorization.

21257392029 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6495867.

The product of its (nonzero) digits is 136080, while the sum is 42.

The spelling of 21257392029 in words is "twenty-one billion, two hundred fifty-seven million, three hundred ninety-two thousand, twenty-nine".